Synthesis and Spectroscopic Properties of 1,2-Diiminetricarbonylrhenium( I)chloride Complexes with Aliphatic Diimines (or 1,4-Diaza-1,3-butadienes) as Ligands

1999 ◽  
Vol 54 (3) ◽  
pp. 341-344 ◽  
Author(s):  
Markus Leirer ◽  
Günther Knör ◽  
Amd Vogler
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Spectroscopic Properties ◽  
Visible Spectral Region ◽  
Partial Charge ◽  
Bidentate Ligands ◽  
Charge Redistribution ◽  
Chloride Complexes ◽  
Diimine Ligands ◽  
Ligand Charge Transfer

Re(1,2-diimine)(CO)3Cl complexes with the aliphatic bidentate ligands diiminosuccinodinitrile (DISN), benzilbisanile (BEAN), bisacetylbisanile (BABA), and benzildiimine (BEDIM) are reported. The compounds show Re(I) to π*(diimine) metal-to-ligand charge transfer (MLCT) absorptions in the visible spectral region. The energy of these MLCT-transitions decreases in the series BABA > BEDIM > BEAN > DISN, depending on the π* acceptor properties of the coordinated diimine ligands. The maxima of these CT bands undergo a solvent-dependent shift (negative solvatochromism), which indicates a partial charge redistribution in the excited state. The compounds are not photoluminescent at room temperature and 77 K.

Syntheses, Structures, Characterisation, and Spectroscopic Properties of CuI and AgI Complexes with Extended C–H···π and π···π Interactions

2014 ◽  
Vol 67 (6) ◽  
pp. 887 ◽  
Author(s):  
Ting-Hong Huang ◽  
Min-Hua Zhang
Keyword(s):  
Charge Transfer ◽  
Room Temperature ◽  
Spectroscopic Properties ◽  
Acetonitrile Solution ◽  
Fluorescent Properties ◽  
Π Interactions ◽  
Π Stacking ◽  
Ligand Charge Transfer ◽  
The One ◽  
Stacking Patterns

Based on the ligands N,N′-bis(pyridin-2-ylmethylene)benzene-1,4-diamine (pmb) and N,N′-bis(pyridin-2-ylmethylene)biphenyl-4,4′-diamine (pmbb), the three compounds [Cu2(pmb) (PPh3)2(Cl)2] (1), [Cu2(pmbb)(CH3CN)2(PPh3)2](BF4)2·2DMF (2), and [Ag2(pmbb)(PPh3)2] (ClO4)2 (3) have been synthesised and characterised. Structural analysis reveals that all of these complexes contain 1D supramolecular arrays, with different variations in π-stacking patterns and intermolecular C–H···π interactions. Crystal structures of 1 and 2 contain 1D tape-like arrays formed by C–H···π and π···π interactions, and an ordered-layer-lattice of DMF and BF4– in 2 is located between the one-dimensional array. For 3, π-stacking interactions lead to the construction of 1D supramolecular arrays and a 2D network. The results indicate that C–H···π and π···π interactions play an important role in the construction of the supramolecular structure. In addition, the absorption peaks of complexes 1 and 3 in the solid state at room temperature show intraligand charge transfer and metal-to-ligand charge transfer absorptions. The optical and fluorescent properties of 2 were also studied in acetonitrile solution at room temperature.

Charge Transfer Interaction in (Riboflavin)tricarbonylrhenium(I) Chloride

1998 ◽  
Vol 53 (4) ◽  
pp. 423-425 ◽  
Author(s):  
Horst Kunkely ◽  
Amd Vogler
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Charge Separation ◽  
Partial Charge ◽  
Charge Transfer Interaction ◽  
Ligand Charge Transfer ◽  
Close Proximity ◽  
Mlct Band

Abstract [Re(riboflavin)(CO)3Cl] shows intraligand (λmax = 476 and 518 nm) and Re(I) to π* (riboflavin) metal-to-ligand charge transfer, MLCT, (λmax = 556 nm, in CH3CN) absorptions in close proximity. The MLCT band undergoes a moderate solvent-dependent shift (negative solvatochromism) indicating a partial charge separation in the excited state. The complex is not photoluminescent.

Synthesis and Photophysical Properties of New Three-Coordinate N-Heterocyclic Carbene Copper Complex

2016 ◽  
Vol 878 ◽  
pp. 18-21
Author(s):  
Shao Bo Liu ◽  
Cheng Yi ◽  
Hong Ying Xia ◽  
Feng Zhao
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Absorption Band ◽  
Energy Absorption ◽  
Copper Complex ◽  
Room Temperature ◽  
Photophysical Properties ◽  
Emission Spectrometry ◽  
Emission Maximum ◽  
Ligand Charge Transfer

A three-coordinateopper (I) complex supported by N-heterocyclic carbene (NHC) ligand and bis [2-(diphenylphosphino) phenyl] ether (POP) ligand were successfully reported and characterized. The corresponding photophysical properties were investigated using UV-vis and emission spectrometry. The lowest-energy absorption band at 343 nm was assigned to metal-to-ligand charge transfer (MLCT) transtion. The emission maximum located at 470 nm upon excitation at 290 nm in PMMA films at room temperature originates from the typical 3MLCT excited state.

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Room Temperature ◽  
Radiative Decay ◽  
Emission Cross Section ◽  
Spectroscopic Properties ◽  
Stimulated Emission ◽  
Different Temperatures ◽  
Stimulated Emission Cross Section ◽  
Semi Empirical

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.

scholarly journals Ultra long‐lived triplet excited state in water at room temperature: Insights on the molecular design of tridecafullerenes

2021 ◽  
Author(s):  
Javier Ramos-Soriano ◽  
Alfonso Pérez-Sánchez ◽  
Sergio Ramírez-Barroso ◽  
Beatriz M. Illescas ◽  
Khalid Azmani ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Molecular Design ◽  
Triplet Excited State

Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution

2021 ◽  
Author(s):  
Chun-Hsiang Wang ◽  
Zong-Ying Liu ◽  
Chun-Hao Huang ◽  
Chao-Tsen Chen ◽  
Fan-Yi Meng ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Room Temperature ◽  
Temperature Solution

Crystal Structures of and Polarized Absorption-Spectroscopy in Racemic and Resolved [Ru(bpy)3] (ClO4)2 and [Zn(bpy)3] (ClO4)2Bpy=2,2'-Bipyridine

1995 ◽  
Vol 48 (5) ◽  
pp. 929 ◽  
Author(s):  
E Krausz ◽  
H Riesen ◽  
AD Rae
Keyword(s):  
Room Temperature ◽  
Energy Difference ◽  
Temperature Structure ◽  
Asymmetric Unit ◽  
Threefold Axis ◽  
Crystal Forms ◽  
The Third ◽  
Racemic Form ◽  
Ligand Charge Transfer ◽  
Dominant Influence

[Zn( bpy )3] (ClO4)2 and [ Ru ( bpy )3] (ClO4)2 are isomorphous in both their racemic and resolved crystal forms. The resolved materials are monohydrates and have a C 2, Z = 8, structure with two independent formula units on general sites in the asymmetric unit. The cations have the same chirality. The inherent threefold axis of each cation lies approximately parallel to the c axis. The unrelated racemic form has a C2/c, Z = 4, structure which is a commensurate modulation of a P3c1, Z = 2, parent structure, typified by the room-temperature structure of [ Ru ( bpy )3] (PF6)2. A primary, secondary and tertiary axis of P3c1 become the c, b and a axes respectively of C2/c, retaining a third of the symmetry elements of P3c1. The crystals grow as multiply contacted twins. This structure bas just one spectroscopic site with the cation lying on a twofold axis that passes through the metal and one of the bidendate ligands and relates the other two ligands to each other. This feature is particularly useful in the study of the optical spectroscopy of the metal-to- ligand charge transfer excitations of [ Ru ( bpy )3]2+ and related systems. A comparison of structural and spectral data indicates that the positions of the anions have a dominant influence on the relative energies of the metal-to- ligand excitations. An energy difference between excitations involving the two (lower-energy) equivalent ligands and the third ligand of the order of 800 cm-1 is indicated in both singlet and triplet regions for the racemic perchlorate. The absorption spectra of [ Ru ( bpy )3]2+and [Os( bpy )3]2+ in a number of crystalline hosts are compared and discussed.

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